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126 lines
4.4 KiB
126 lines
4.4 KiB
/* |
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* Copyright (c) 2010 Stefano Sabatini |
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* Copyright (c) 2006 Ivo van Poorten |
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* Copyright (c) 2006 Julian Hall |
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* Copyright (c) 2002-2003 Brian J. Murrell |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License along |
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* with FFmpeg; if not, write to the Free Software Foundation, Inc., |
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
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*/ |
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/** |
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* @file |
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* Search for black frames to detect scene transitions. |
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* Ported from MPlayer libmpcodecs/vf_blackframe.c. |
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*/ |
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#include <stdio.h> |
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#include <inttypes.h> |
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#include "libavutil/internal.h" |
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#include "libavutil/opt.h" |
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#include "avfilter.h" |
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#include "filters.h" |
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#include "video.h" |
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typedef struct BlackFrameContext { |
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const AVClass *class; |
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int bamount; ///< black amount |
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int bthresh; ///< black threshold |
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unsigned int frame; ///< frame number |
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unsigned int nblack; ///< number of black pixels counted so far |
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unsigned int last_keyframe; ///< frame number of the last received key-frame |
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} BlackFrameContext; |
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static const enum AVPixelFormat pix_fmts[] = { |
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AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NV12, |
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AV_PIX_FMT_NV21, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV411P, |
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AV_PIX_FMT_NONE |
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}; |
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#define SET_META(key, format, value) \ |
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snprintf(buf, sizeof(buf), format, value); \ |
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av_dict_set(metadata, key, buf, 0) |
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static int filter_frame(AVFilterLink *inlink, AVFrame *frame) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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BlackFrameContext *s = ctx->priv; |
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int x, i; |
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int pblack = 0; |
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uint8_t *p = frame->data[0]; |
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AVDictionary **metadata; |
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char buf[32]; |
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for (i = 0; i < frame->height; i++) { |
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for (x = 0; x < inlink->w; x++) |
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s->nblack += p[x] < s->bthresh; |
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p += frame->linesize[0]; |
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} |
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if (frame->flags & AV_FRAME_FLAG_KEY) |
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s->last_keyframe = s->frame; |
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pblack = s->nblack * 100 / (inlink->w * inlink->h); |
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if (pblack >= s->bamount) { |
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metadata = &frame->metadata; |
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av_log(ctx, AV_LOG_INFO, "frame:%u pblack:%u pts:%"PRId64" t:%f " |
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"type:%c last_keyframe:%d\n", |
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s->frame, pblack, frame->pts, |
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frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base), |
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av_get_picture_type_char(frame->pict_type), s->last_keyframe); |
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SET_META("lavfi.blackframe.pblack", "%u", pblack); |
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} |
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s->frame++; |
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s->nblack = 0; |
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return ff_filter_frame(inlink->dst->outputs[0], frame); |
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} |
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#define OFFSET(x) offsetof(BlackFrameContext, x) |
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#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM |
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static const AVOption blackframe_options[] = { |
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{ "amount", "percentage of the pixels that have to be below the threshold " |
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"for the frame to be considered black", OFFSET(bamount), AV_OPT_TYPE_INT, { .i64 = 98 }, 0, 100, FLAGS }, |
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{ "threshold", "threshold below which a pixel value is considered black", |
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OFFSET(bthresh), AV_OPT_TYPE_INT, { .i64 = 32 }, 0, 255, FLAGS }, |
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{ "thresh", "threshold below which a pixel value is considered black", |
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OFFSET(bthresh), AV_OPT_TYPE_INT, { .i64 = 32 }, 0, 255, FLAGS }, |
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{ NULL } |
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}; |
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AVFILTER_DEFINE_CLASS(blackframe); |
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static const AVFilterPad avfilter_vf_blackframe_inputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_VIDEO, |
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.filter_frame = filter_frame, |
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}, |
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}; |
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const AVFilter ff_vf_blackframe = { |
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.name = "blackframe", |
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.description = NULL_IF_CONFIG_SMALL("Detect frames that are (almost) black."), |
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.priv_size = sizeof(BlackFrameContext), |
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.priv_class = &blackframe_class, |
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.flags = AVFILTER_FLAG_METADATA_ONLY, |
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FILTER_INPUTS(avfilter_vf_blackframe_inputs), |
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FILTER_OUTPUTS(ff_video_default_filterpad), |
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FILTER_PIXFMTS_ARRAY(pix_fmts), |
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};
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